Yes it sucks, but at least you have some here that have gone through it. When it happened to me I posted on here, and thebrick really helped me sharing his experience, he really encouraged me a lot; in fact I still need to meet up with him and buy him that beer I told him I owed him.
The PT I first had was an out of shape guy, had book smarts but not in physical shape at all, so he didn't really understand our mindset, about 3 weeks into it they changed me to a lady in her early 50s that still runs marathons and triathlons, lifts etc, so she was great and pushed me way further than I would have thought possible. She had me doing what I thought was silly shit, like balancing on a bosu ball while bouncing a tennis ball off a board over and over, going up and down a slightly inclined ramp, focusing more on the control of the descent which was my weakness.
As far as range of motion work, she ended each session with slow bending which really did hurt and scared me, thinking I was gonna snap something. One thing she did was massaging and pressure points in the quads that help release lactic acid I think she said ( which also hurt), but as soon as it released the pain wiuld subside and I could bend further. Read up on that in case your PT isn't aware of that, it made a big difference.
As soon as you're able, the recumbent bike as much as you can stand is your friend. I think that helped me get back more of my list size than anything. Even now I'm doing it at least 20 minutes a day, always about 10 minutes before squats or presses, kind of like the pre exhaustion method, seems to lessen the strain on the knees.
Keep us updated on your progress!